Link aggregation or trunking enables the connection of two networked devices, such as network devices, computers, end stations, etc., by grouping multiple physical network links between the devices into a single logical link. For example, administrators of a network aggregate several Ethernet links together into a link aggregation group (LAG) as defined in the IEEE 802.3ad standards. By setting up a LAG based on these standards, the network appears to run on a single Media Access Controller (MAC) that distributes and load balances the Ethernet packets between the group of physical links in the LAG.
Link aggregation provides for greater redundancy, such that if one of the physical network links fails, another physical network link of the same logical link may be used. Additionally, grouping multiple physical network links may increase the bandwidth capacity of the communications channel between the two devices and may provide load balancing over the physical links that are grouped together.
Typically, all the physical links that comprise the single logical link operate in a full or near-full power state. As such, the power consumption demands of the logical link may result in under-utilization of the bandwidth capacity when demand is low.